I stumbled upon a study in which distinct SNPs in the fetal haemoglobin of Llamas supposedly made their erythrocytes to have more affinity towards oxygen, giving an advantage in their high altitude habitat, contrary to their camel cousins who lacked such mutation. Is it possible to retrace this back to humans?
Dear Rajit ,
im not genetic expert .. just astrobiologist .Dont' you think better to go with paleo habitat . Biogeographical variation can be effected to genetic too. See Two branches of a Homo erectus exodus out of Africa could both have the genetic mutation that resulted in Homo sapiens springing up in two different location, it is probably highly unlikely, but possible. Three or more locations to have the same genetic mutation would be near impossible. Recent DNA testing indicates that Homo Sapiens left Africa, but some of them returned many thousands of years later.
On purely speculation, what could be a more likely scenario is that an early predecessor to Homo sapiens left Africa, developed into Homo habilis or another species, then returned to Africa where they then continued to changed until Homo sapiens developed. Hominidae appear to have developed in what would become southern Europe, southern Asia/India, and eastern Africa. There were Hominids in India knapping Acheulean artifacts during the late middle Pleistocene. Could a species develop in the Ganges River Valley or Yellow River Valley and then return to Africa to further develop while that lineage died out?
The question also is how complete is our fossil record? At this point not very complete at all. Do we find more early fossils in eastern Africa because of better preservation than some other locations, like India or China? I am sure someone has looked into that. Still, we possibly have fossil evidence for only a tenth of the Hominid line, maybe more, maybe less. While paleoanthropologists have sequenced the fossils that we have, it is now looking like there were many hominid species running around Africa at the same time. Who knows how many more branches and dead ends of the family tree there are as yet undiscovered. And why Africa? More biodiversity? More competing species? More competition period? & why high altitude ?
Dear Rajit,
It is simply an example of adaptation. In human beings also people inhabiting the hilly regions have greater haemoglobin content in their blood cells than those living in plains. It is high altitude adaptation to cope with oxygen stress. The other striking example is sickle cell anaemia which occurs in human population inhabiting the regions where the disease malaria is rampant. Sickle cell anaemia is an cultural adaption to cope with malaria.
Good luck